Gov. Cuomo won wide respect last spring after he stood up to public-sector unions with a responsible budget and property-tax relief. Today, he can show that he still gets it — by vetoing a typical Albany pension-sweetener bill.

The legislation, which will become law unless he vetoes it by at midnight, would let city cops and firefighters keep their pensions even if guilty of wrongdoing — so long as they’ve put in at least 20 years of service.

Huh?

Not only would this further fuel runaway pension costs (already up nearly eight-fold in the city over the past decade), it’d also end a powerful disincentive for misconduct, including committing crimes.

That lawmakers would even pass such a bill is proof positive that Albany’s political corruption — their habit of showering unions with gifts, at public expense — lives on, even in the Age of Andrew.

Sure, the Assembly, run by labor’s Democratic lapdogs, can be relied on to back such mischief (though New Yorkers might have thought Cuomo’s strong push for meaningful reform might have made a difference there).

But for the Senate, which Republicans won last year on a vow to be more frugal and ethical, to go along is beyond disappointing.

Indeed, Cuomo himself should have promised a veto right at the start. (Even then-Gov. David Paterson had the sense to kill a similar bill last year.)

Alas, Cuomo’s view remains a mystery; New Yorkers won’t find out until today.

No wonder Mayor Bloomberg is fretting: Last month, he fired off a letter to Cuomo urging him to nix the bill.

“The legislation … would remove a powerful incentive for long-term employees to honor their oaths of office,” he wrote.

Although felony convictions could still lead to the loss of pensions under the bill, he noted, other types of wrongdoing — misdemeanors, felony acquittals on technical grounds, serious departmental violations and drug use — could not.

Again, Cuomo should never have let this pass. If he doesn’t veto it, his reformer reputation will take a well-warranted hit.